1. Field of the Invention
The present invention relates to an automatic focusing device, and more particularly, to an automatic focusing device that can keep an object in an in-focus state even in the case where there is change in the direction of the velocity or acceleration of the object with respect to the camera such as in the case where the object makes an U turn movement in front of the camera.
2. Description of the Related Art
An automatic focusing device is proposed that follows the movement of an object to keep an object in an in-focus state (for example U.S. Pat. No. 4,860,045). This automatic focusing device can keep in an in-focus state for an object that does not change in the direction of velocity or acceleration with respect to the camera.
In such an automatic focusing device it is inhibited to try to keep an object in an in-focus state when the direction of velocity or acceleration of the object with respect to the camera is reversed, such as in the case where an object makes an U turn movement in front of the camera. This is because the movement of the object can not be followed if the focus detecting operation is continued identical to that employed before the object changes its reverse direction of velocity or acceleration.